I have a number of video clips that I've been editing w/ kdenlive that I'd like to burn to bluray (~24GB of 720p 16:9 12Mbps encoded x264 video files). My desktop also has a plextor bluray burner attached w/ standard and dl bluray media. I'm wondering what the best process would be -- this does not seem to be documented anywhere. Is it the same as dvd? My worry is that the standard dvd builder wizards will try to re-encode the files to mp2 and/or downgrade video to SD. Also, most of them assume the max disc size is 8.4GB.... I have heard that k3b currently supports burning to bluray so all I really need is process to create the iso.

Blu-ray output with Free Software is still immature. Only recent did the encoder gain compliance:
http://x264dev.multimedia.cx/?p=328

That does not cover any of the "authoring" features like title, chapters, and interactivity. I have no idea what is available for that. Burning is great and all, but it just burns data, and getting the data correct is entirely another matter. I do hope anyone with experience or knowledge in this area will comment. Certainly, you can get tons of more information on doom9.org, but sorting through it all may take some time.

Yes, doom9 is the right place. Take a look at "multiAVCHD" (Windows). With it you can create BD structures, menus and so on.